The popular messenger service WhatsApp will stop working on BlackBerry, Symbian and Windows devices sometime this year.

While celebrating its 7th anniversary, WhatsApp through a blog post announced that they will be withdrawing support for BlackBerry OS (including BB OS 10), Symbain 60, Symbian 40, Windows Phone 7.1 and devices running on Android 2.1 and 2.2 devices.

The post stated, "When we started WhatsApp in 2009, people's use of mobile devices looked very different from today. The Apple App Store was only a few months old. About 70 percent of smartphones sold at the time had operating systems offered by BlackBerry and Nokia. Mobile operating systems offered by Google, Apple and Microsoft - which account for 99.5 percent of sales today - were on less than 25 percent of mobile devices sold at the time."

WhatsApp will withdraw the support for the above mentioned OS by the end of this year. The company believes that while these mobile devices have been an important part of the story, they don't offer the kind of capabilities WhatsApp need to expand app's features in the future.